有机化学实验在线开放课程设计的探索与实践

针对以往有机化学实验教学中存在的问题及学生所反映的改进期望,在有机化学实验在线开放课程的开发中,充分利用在线课程与网络教育平台,制作了针对性的教学微视频课程和相应的课件,建立了一套完整的测试模式与题库。通过考测机制,促进和强化学生的实验课前预习。而学生在充分预习的基础上,实现实验预习–现象记录–实验报告完整规范化和一体化,相应提高了学习效率。同时,建立了一套相对客观的成绩评估体系并取得了积极的成果。     

Correlation of Lithium Ionic Diffusion with Nb Concentration in Li7-xLa3Zr2-xNbxO12 Evaluated by an Internal Friction Method

Solid lithium-ion conductors Li7-xLa3Zr2-xNbxO12（x =0.25, 0.5, 1, 1.5） with cubic garnet structure are suc- cessfully prepared by a solid state reaction method, and the effects of Nb concentration on lithium ion diffusion are investigated by means of internal friction （IF） technique. A prominent relaxation-type IF peak （actually composed of two components） is observed in each Nb doped LiTLa3Zr2012 compound： with apeak PL at lower temperature and a peak PH at higher temperature. The mechanisms of the two components are suggested to be associated with two diffusion processes of lithium ions via vacancies： 48g ←→ 48g and 489 ←→ 24d. The relaxational strength of the IF peak gradually decreases, which is accompanied by the activation energy increasing from 0.45 eV to 0.64 eV with the increasing Nb doping level. The corresponding mechanism is ascribed to originate from lattice contraction as well as the lower concentration of diffusion ions induced by the substitution of Zr4＋ by Nb5＋.     

有机化学与实验课程在线“双练教学”模式的探索与实践

在有机化学与实验在线课程中,采用课前、课后开放式或半开放式小测练,在网络教学平台上探索以练促学的"双练教学"模式。通过"双练教学",学生的学习状态、自信与积极性得到了改善和提高。同时,教师通过在线学生成绩数据分析、问卷和互动反馈,及时了解和掌握学生的学习状况并适时调整教学内容,在线上教学中取得了良好的效果。